Irrigation systems and sewer systems are two of many types of underground operations in which fluids are passed through piping to move a type of fluid from one location to another. In irrigation systems and sewer systems, a matrix of conduits are disposed in the soil connected together by fittings, joints, connectors, valves, and other components that establish the pathways for the fluid to navigate from a source to a destination. Many components of current fluid transport systems are made from lightweight plastics such as polyvinyl chloride (“PVC”), polyethylene, HDPE, and Styrene. Where the junctures of two adjacent components are formed, e.g., conduits or fittings, the mating of the two components are typically secured by either a threaded connection or a press fit connection bolstered by an adhesive selected especially for the material(s). Where adhesives are used to bond two mating fluid couplings, they are generally effective at preventing leaks, but the main function is to keep the conduits and fittings fixed together in a working mechanical relationship. Over time, the connection between the adjoining components may slip or adjust due to a variety of external conditions, such as varying loads from the soil shifting, torqueing of the lines, age, wear, and the like, along with internal conditions such as pressure variations, leading to minute separations of the mating components and a small amount of enclosed fluid being released into the adjacent soil. This small amount of fluid is usually not so great as to require that the conduit be replaced or repaired, but moisture in the soil can lead to other problems.
One issue that arises in this situation where a minute leak of water into the soil surrounding the piping acts as an attraction for migration of vegetation to the location of the leak. Small amounts of water in the soil can attract roots of trees, plants, grasses, or the like, which when in proximity with a weakness in the piping can then invade the conduits at the joints through the small separations. This intrusion of vegetation into the conduit, especially at locations where the conduit may be weakened through age or damage, can cause more damage and exacerbate the leaks. Tree roots can also pass into the conduits through cracks at the leaks, clogging the piping if left to grow and expand, and the presence of the roots can also introduce unwanted impurities in the fluid transport system. Roots have been known to destroy an underground piping system and require expensive repairs or even replacement if left untreated. To remove the roots, excavation and manual extraction of the roots are routinely required, which can be both costly and inconvenient.
The use of selected materials in irrigation systems are known to resist intrusion of roots and vegetation. Westman, U.S. Pat. No. 4,647,072 taught a repair sleeve for a pipe fitting that included a coating of copper sulfate to inhibit root growth in the repair fitting. Tobiason, U.S. Patent Publication No. 2013/0102469 taught the use of herbicides to sewer lines to prevent vegetation growth in the lines. Scheubel, U.S. Pat. No. 5,575,112 taught a fabric made of a water-permeable synthetic fibers coated with an inorganic copper compound as part of a method for controlling the growth of plant roots. However, each of these proposals and solutions have drawbacks in the real world that make them impractical to implement and costly or ineffective.
Accordingly, the present invention seeks to address the situation of root invasion into underground piping systems using a growth deterrent in the system's adhesive to repel or deter moisture seeking roots and vegetation near vulnerable or damaged fittings of an underground fluid delivery system from entering the system.